Integrated waveguide coupled Si_3N_4 resonators in the ultrahigh-Q regime

摘要: The vast majority of work on waveguide-coupled resonators focuses decreasing losses in the waveguide and coupling region. Here we present fully integrated based an ultralow-loss Si3N4 platform. By tailoring directional coupler excitation to resonators, are able achieve lower loss single-mode multimode widths compared straight bus couplers. This allows us demonstrate record-high coupled intrinsic quality factor (Qint) values 81 million at a 9.65 mm bend radius, with future direction both stronger waveguide–resonator coupling. result opens up integration possibilities for narrow linewidth diode lasers, low noise feedback systems, microwave photonic research, ultrastable timing reference community.